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5

As others have said, the skater would move faster if he simply pointed the leafblower behind him, rather than bouncing it off the umbrella. However, there is a real use for this technique. Jet engines normally suck in air from all directions and blow it out of the back in order to move forward. However they are also capable of reverse thrust if fitted with ...


25

Firstly, this gif is not accurate unless the fan is really strong. Seemingly, even if the skateboarder is being propelled forward, the fan wouldn't blow a hard enough wind to cause this effect. The concept of blowing your own sail really does have to do with conservation of momentum. In that very episode of Mythbusters you speak of, the sail was removed, ...


5

The question is whether this is a form of "pulling yourself up by your own bootstraps". Clearly the driving force here is the leafblower the skater is wearing, which takes ambient air with zero average momentum and sends it out a vent with large average momentum. One would expect, absent some deviousness having to do with turbulence, that the skater would ...


9

Of course it's possible. The air is blown forwards and bounces off the umbrella. The net flow is to the back. Then its a question of conservation of momentum...


0

Based on what we know, both from science and philosophy, these are both ill-phrased questions. You can get as many answers to them as you like, and they will all be equally meaningless, because none will bare any logical relationship to known facts about the universe we live in. Now, there are much better question along these lines, which deal with the ...


1

Actually... There is a branch of physics that attempts to answer that question. It's called Physical Cosmology. Among many other things, cosmologists want to know why the physical laws are as they are. The trouble is, there just are not that many other universes ready for us to compare. We also don't know what is going on with most of our universe, like ...



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